A Piece of DNA

In one of the drawers in my father’s office, I found an unmarked, unsealed, old padded envelope. It seemed to have something hard inside. I reached in and pulled out a flat piece of metal about the size of both my hands together. It was shaped like a hexagon, with a splotch of green paint in the middle and a spoke welded to each corner; the spokes were not all the same length.

I stared at it, puzzled. Then I noticed a single word, written on it in pencil: “Cytosine.” And I knew what it must be.

Wow. I had no idea my father had this. It’s the biology equivalent of a piece of the true cross: a piece of the original model of DNA built by James Watson and Francis Crick in the spring of 1953. The model that revealed the structure of DNA for the first time.
DNA; deoxyribonucleic acid; the double helix; the stuff of which genes are made; the fundamental material of evolution.

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Part of the original model of DNA built by James Watson and Francis Crick in 1953. This is one of the bases — cytosine.Credit

And part of my life for as long as I can remember. When I was a little girl, and we were living in England, my father was writing his Big Book, a history of molecular biology called “The Eighth Day of Creation.” The first part of the book describes the discovery of the structure of DNA, so it was a molecule that got a lot of airtime at home. I remember, when I was about 7, standing in the study my father had in the old Victorian house we were renting, as he showed me a small glass vial with some white flakes at the bottom, and explained to me that this was DNA. (I knew I was supposed to be impressed — and I knew that DNA stood for deoxyribonucleic acid — but I had no real idea what that meant, and much preferred to be outside, climbing the apple tree.) Then, when I was in seventh grade — by now, we were living in Baltimore — and casting around for a school science fair project, my father suggested that I build my own model of DNA, out of Styrofoam balls and wooden dowels, according to instructions in a large red book.

The balls were duly ordered from a place in the Bronx (“the largest Styrofoam ball manufacturer in the world,” as I recall), different sizes for the different atoms. I painted them (red for oxygen, black for carbon, and so on), and proudly assembled my double helix at home. (My journal from the time reports, “I spent all day building DNA. It was very frustrating, because every time I put an atom on, another atom fell off. I had to use a lot of glue.”) But the way to school was full of potholes — such were the roads in Baltimore, then and now — and, glue notwithstanding, it shook apart in the car. On getting to school, I had to build it all over again. Besides, the teachers wanted us to do experiments — what happens if you leave human teeth immersed in various soft drinks for three weeks, that sort of thing — so it was not much admired, and was dismantled soon after the fair was over. All that survives is an old photograph, taken at home before the pothole fiasco, of me (long braids, a flowery skirt, the slouching posture of an anxious adolescent) and my little painted model. Not at all like the famous photograph of Watson and Crick with theirs, Watson gazing upward, Crick gesturing confidently, and DNA, spidery and thin and metal, spiraling high between them.

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Naturally, my father wrote about their model in his book: “That morning, Watson and Crick knew, although still in mind only, the entire structure [of DNA]: it had emerged from the shadow of billions of years, absolute and simple, and was seen and understood for the first time…Toward the middle of the next week, when at last the machine shop delivered the flat metal pieces, Watson and Crick began to build the model. These pieces were thin plates of galvanized sheet, cut to the shapes of the purine and pyrimidine rings, with brass rods, three millimeters thick, welded to the corners, sticking out and cut to the right lengths for the bonds. The pieces were joined by brass sleeves slipped over the tips of the rods and fixed by set screws; they must have been infuriating to build with. The piece in front of me is labeled ‘Cytosine’ on both sides in Crick’s hand, and color-coded with a dab of shiny green…In a mounting rush of excitement, they completed a full model by Saturday evening, March 7.”

Here’s a coincidence: My journal reveals that I built my model on a March 7, too. But at some point, despite its historical importance, their model was also dismantled — which is presumably how my father came to have a piece of it. (The model on display at the Science Museum in London is a 1970s reconstruction, albeit from some of the original parts.)

DNA; deoxyribonucleic acid; the stuff of which genes are made; the fabric of inheritance. The metal plate is cool in my hands. As I look at this relic that could easily be mistaken for a nondescript piece of scrap metal, fragments of family history flicker through my mind — great-great-grandparents on my mother’s side, part of Imperial Britain, who were married in Calcutta Cathedral in 1867; my father’s ancestor, known in the family as “the original Horace Judson” who fought for the North in the Civil War and whose saber we still have; and his forebears, religious Puritans I suppose, who came to the American colonies from the north of England early in the 17th century.

Then the frame shifts, and I seem to see the way the double helix connects every life-form on the planet, through a lineage that can be traced back billions of years, to the dawn of life on earth. And here I am, sitting among filing cabinets and bookcases and stacks of paper, holding a fragment of the object that first revealed how it all works.

Olivia Judson is an evolutionary biologist and writer based at Imperial College London. The author of “Dr. Tatiana’s Sex Advice to All Creation” and a former online columnist for The New York Times, she is working on her next book.

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Olivia Judson is an evolutionary biologist and writer based at Imperial College London. Ms. Judson has been a reporter for The Economist and has written for a number of other publications, including The Atlantic and National Geographic. She is also the author of “Dr. Tatiana’s Sex Advice to All Creation: The Definitive Guide to the Evolutionary Biology of Sex,” and a former online columnist for The New York Times. She is currently visiting das Wissenschaftskolleg zu Berlin, where she is working on her next book.